Rule clamp



Marchl19, 1940. J. E. HAs'rxNGs 2,194,085

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ATTORNEYS.

March 19, 1940. J. E. HAsTlNGs RULE CLAMP 2 Sheets-Sheet 2 Filed May 18, 1939 INVENTOR. Tanzes L. ./sangs ATTORNEYS Patented Mar. 19, 1940 rATENT` OFFICE RULE GLAIMP .lames E. Hastings, Athol, Mass., assignor to lThe L. S. Starrett Gompany, Athol, Mass., a corporation of Massachusetts Application May 18, 1939, `Serial No. 274,340

4 Claims.

Clamping devices for straight edges of various sorts have long been involved in the technique, as well as part of theequipment of the modern mechanic, but while developed in various styles 6 or types, they have all shown an annoying fault of wabbling or otherwise undesirably moving when in untightened positions. Because the clamp screw is normally untightened or slack when the user is trying to set up a straight edge assembly for his work, any `unexpected free or accidental movement, resulting in jiggling or wabbiing of the screw shank with corresponding uncertain'positioning of its foot, has caused a considerable amount of Aumbling at critical moments. IThis usually occurs just at the very time when it is most desired to secure a nicety and accuracy of relative disposition of the parts so as to obtain accurate reading of their graduations. It also has involved a loss of time on the work or job at hand.

Various efforts havev been made to overcome this difficulty, and While some corrective devices have been designed and tried, they have not been satisfactory from either standpoint of function-` ing in use or from the basis of cost of production.

It has been proposed to apply friction to the clamping stems or 'tightening nuts, but the suggested friction devices have usually been inconvenient of adjustment, or, when exposed so as to be readily accessible, they have had the fault of catching on unrelated objects, or gathering dirt, to the vexation of the tidy mechanic and even to the lessened eiiiciency of the tool or instrument being used.

My concept is one capable of simple but elicient and inexpensive embodiments. These I have de-v vised as blind or concealed members, but capable of ready adjustment of tension or friction.

As illustrative of my Ainvention in some of its characteristic applications, I have shown several forms in the accompanying drawings which are not only satisfactory and practical for production and use, but are suggestive of other variants which will doubtless occur to those skilled in these matters. I

Throughout the specication and drawings like reference characters are employedvto indicate corresponding parts, and in the drawings:y

Fig, 1 shows. a characteristic type of angled clamp attachment for straight edges according to my invention, with the scale members indie cated as disposed at right angles to each other'.

Fig. 2 is a partial vertical section on the line 2 2, of Fig. l through the threaded Aclamp hook.

(Cl. 33 103) y Fig. 3 is a similar view on the indicated line 3 3, of Fig. 1.

Fig. 4 is a transverse section on the indicated line 4 4, of Fig. 1. v

Fig. 5 is a detail of the friction piece of Figs. l-Jl, inclusive.

Fig, 6 shows an angle clamp with a modiied form oi' friction system, and partly sectioned to show one of the concealed assemblies.

Fig. 'll is a partial sectional view on the line l l', of Fig. 6.

Fig. 8 is a corresponding section on the line 8 8, of Fig. 6.

Fig. 9 shows an angle attachment with another type oi friction member for the clamp.

Fig. l0 is a section as indicated on the line iii-lil, of Fig. 9.

Fig. 1l illustrates another type of clamp as v for rulers in alignment with the friction system of Figs. i-l, inclusive, partly broken away to expose its concealment, and

Fig. 12 is a section on the line i2-l2, of Fig. 11.

Referring to the angle head or attachment best lillustrated in Figs. 1 4, inclusive, I provide an angled head member l of usual and generally accepted type channelled at la to receive the usual blade 'B of a square or like instrument or tool with a groove b which is adapted to be engaged by the foot 2 of a screw clamping member lying in theinternal transverse groove ib. The screw threads of the member '3 are nterrupted above the foot 2 to nearly its upper end so as to give a flat face i adapted to make clamping contact'with the blade B.

At its upper end as at 5 the stem of the clamp 3 is fully threaded to receive a knurled nut 6 having a depending cylindrical sleeve-like base l (Fig. 3). This base 'i'which is' adapted to enter the bearing portion 8 of the stem receiving aperture 9 which communicates with the groove I b is circumferentially grooved or channelled as at l0. This groove I0 has a double function in that it provides` a concealed friction bearing within the head I and also acts as a retainer for the clamp assembly to support it from sagging vertically or wabbling out of the perpendicular.

In the embodiment of my invention shown in Figs. 1-5, the groove i0 is engaged by a lateral shank I i of a bent frictioning piece Il preferably of general U-shape. This frictioning piece Il is of fiat metal stock with a slight spring tension in its bow H2 so that its face H3 may come in contact with the adjacent wall of a longitudinal receiver or Well i2 which intersects the transverse groove Ib. The shorter arm I I of this frictioning piece nts into the circumferential groove I0, the longer arm H4 being partially cut away so as to lie beneath the shoulder 8 of the bearing portion 8 of the nut B, the edge II5 bearing against the extreme top portion of the stem 5 of the clamp 3 and the extension IIa extending past the stem 5 further into the bottom of the Well I2.

The friction and holding piece I I is pressed by a follower spring I3, the tension of which is adjusted by a screw I4 tapped into the end of the aperture of the receiver I2. As the screw I4 is exposed at the end of the head I it is perfectly easy for the mechanic to vary or adjust the tension or friction of the frictioning piece II on the upper end of the clamp 3 by turning up or slacking-off on the screw I which has a fiat head end lying ush with the end of the head I so as to expose its slots I4' without itself protruding beyond the end face of the head.

This type of frictioning device I I is particularly important in connection with the rule receiving clamp I6 which has a hook or foot I'I threaded as at I8 opposite its dat face I9 and fully threaded as at 25 at its upper end for receiving the knurled nut 2|. 0n the nut 2l is a depending sleeve 2 having circumferential groove 2%. The sleeve 2 is supported in a bearing 28 at the upper end of the threaded screwclamp aperture.

The clamp screw i6 had a usual half round bearing groove I6 in the head I which intersects the receiving channel I5 for a ruler R. These rulers may be of any type that the mechanic may happen to have in his kit, the edge r being drawn under an inclined shoulder having a slight bevel I5 for receiving rules, regardless of their thickness, and for drawing them inwardly against the rear wall of the rule receiving channel I5.

The frictioning and receiving system of Figs. 1 5 inclusive is most important in the open sided rule receiving slot I5 as otherwise the threaded screw hook or clamp I6 would tend to dangle or wabble. It preferably is applied also to the blade engaging clamp 3, although it is not as necessary because the blade B has a smooth sliding fit within the blade channel 9 of the head I. It does, however, also have its supporting function for the clamp 3 in the bearing of its portion I I3 against the upper or outer wall of the groove ID. This permits it to maintain the clamp 3 resiliently so that as the nut is turned to find the groove b in any width of blade B that may be employed, the clamp 3 may be axially moved against the slight resilience of the shank II' to get the foot accurately aligned with the groove b. This frictioning system may also be used in other attachments or tools and more particularly as will in part be later specifically pointed out herein.

Referring to Figs. 6, 7 and 8, I have shown a modification in accordance with my invention in which the knurled head 3l has its depending sleeve or cylindrical portion 31 circumferentially grooved as at 3U to receive the blunt end of a combined friction piece and support 32 followed up by the tensioning spring 33 and adjustably backed up by the concealed screw 34 having its slotted head 34' exposed at the end of tle frame |00 in general similarity to the system shown in Figs. 1 4. The depending sleeve 31 is supported in a cylindrical bearing 38 at the top of the aperture of the clamp screw 36. The tension or friction on the threaded stem 3S may thus be readily varied or adjusted by the user without having to open up the interior parts.

As a further modification of my invention I have shown in Figs. 9 and l0 a frame 200 having a knurled nut 4I and depending interior sleeve portion 41 and grooved circumferentially as at 45 to receive the rounded end of the combined friction and supporting screw 44 having a slotted adjusting head 44.

In Figs. 11 and 12 I have shown my invention applied to a rule clamp 500 having its rule receiving undercut 5I5 open on one side and adapted to receive a pair of rulers or other straight edges end to end (not shown) to give the mechanic as long a combined straight edge as his available equipment will afford, by the use of this clamp.

As the rules 0r blades so clamped are a part of the equipment already in the tool box of the workman, he is provided with a long rule, even longer than his box will accommodate. The head portions of the rule clamps S are provided with the usual blade clamping hooks 56 footed as at 52 and screw threaded as at 55 to receive a nut 5I. This nut 5I has a depending cylindrical portion 5l in which is a groove 6l) receiving friction piece 6I having an end 6I which is followed up by the blind screw 64 having a slotted head 64', one at each end of the head 500, for adjustment.

The operation and function of the friction piece in such a clamp as 500 is much similar to that shown in Fig. 1 and needs no further description as its advantages will be readily familiar to those with shop usages and practices in setting up graduated straight edges or rules in end to end relation to get the maximum length of the users tool box resources.

The modifications shown, as before suggested are not only illustrative and suggestive of other` modifications and variants, but they represent simple and efiicient forms well adapted to factory production at reasonable cost.

What I therefore claim and desire to secure by Letters Patent is:

1. In a clamp for straight edge blades, a frame, blade bearings on the frame, a blade clamp comprising a threaded stem, a clamping foot at the stem end, a clamp bearing in the frame and having a grooved bearing wall for guiding said stem, a nut threaded to said stem, a depending cylindrical base on the nut and having a peripheral retaining groove, said frame also having a bore radially intersecting said clamp bearing, a friction clip in said bore and having an arm lying in said peripheral groove, and a second arm in said bore extending inwardly of said intersection and groove within the frame exterior so as to be thereby concealed, a resilient follower for said clip, and an adjustable backing piece for said clip in said bore and threaded in its outer end to seal it externally of the frame.

2. A blade clamp, comprising a frame having a blade bearing and a clamp bearing, said clamp bearing terminating at its upper end in an enlarged recess, a threaded clamping stem in said clamp bearing and having a shoulder, a nut threaded on the upper end of said stem and having a depending reduced base seated in said recess, said frame also having a bore intersecting said recess, and a friction detent concealed in said bore and having a portion engaged with said nut base below the upper face of said frame to limit longitudinal movement of said stem in its bearing, and having another portion presenting a lateral edge engaged with the shoulder of said stem to hold said stem against rotation when the nut is turned on it.

fill

l wards the outer end of said bore, and a resilient member in'saidbore acting upon the bowed portion of said detent. l y

`4. A blade clamp, comprising a frame having a blade bearing and a clamp bearing, a threaded clamping stern in said clamp vbearing having a shoulder between its ends and having blade en- 10 gaging means at one end and having an operating nut at its other end, said frame also having a bore intersecting said clamp bearing, and a friction clip concealed in said bore andl having a portion engaged with said nut below the upper face of vsaid. frame to limitl longitudinal movement of said stem in its bearing, and having another portion presenting a 'lateral edge engaged with the shoulder of said stem to hold said stem against rotation when' the nutvis turned on it,

, JAMES E. l-IASTINGS. 

